Lauterbrunnen is a very small village and easy to get around by walking.
The Lauterbrunnen area is famous for mountainbiking. Rent an Interlaken bike (for eg, there's a rental store at the West station) and ride to the end of the valley the place called Stechelberg. For sFR.20.- take your bike in the gondula up to Mürren. From Mürren follow the red bike trail signs to Winteregg. It is an easy trail for everybody, not much up hill. From Winteregg enjoy a fast downhill to Isenfluh or back to Lauterbrunnen. This tour can also easy be started in Interlaken: it is only 45 minutes more biking, and the round trip from Interlaken needs 3-5 hours. Get your great quality bike maps and all information at rental places in Interlaken. This can also be done in the other direction. Rent a bike in Lauterbrunnen (two options, the bike shop opens at 900 and has 2h, 4h, 8h options (20/28/38 CHF). You can then either follow the Lauterbrunnan loop bike route 450 which climbs up to Grütschalp or take the cable car with your MTB (6CHF June 2019 plus 3.5 for the bike, bike fee inconsistently charged but we had to put it in the luggage tray, in quiet times it may be possible to take the bike on board. Be sure to tell them you are going only to Grütschalp so you are not charged the whole fare to Mürren as the cable car connects with the train to Mürren). Then you cycle along the ridge via Winteregg to Mürren and descend to Grimmelwald. This is spectacular, easy and requires moderate fitness but be warned, after Gimmelwald the descent to the valley floor has some rather aggressive single track of lose shale. Be prepared to walk your bike a good distance (30 min or so) or you can take the cable car to Stechelberg to avoid this (6 CHF, inconsistently charged). There is a nice restaurant in Stechelberg for a rest before the flat ride through the valley back to Lauterbrunnan. You will also pass Trummelbach Falls on the east side of the valley.
Swiss chocolate, made fresh in the shops as you sit and drink coffee.
Cities close by include: